This project will continue investigation on the details of the metabolic pathway of neutral sterols to bile acids, particularly aimed at: a) elucidation of the pathway from cholestanol to allo bile acids, b) an investigation of the details of 12 alpha-hydroxylation in relation to the formation of 5 alpha and 5 beta bile acids, c) exploitation of improved methods of rapid HPLC separations of conjugated bile acids, and development of a computerized data acquisition system for GC-MS analyses of bile acids and their derivatives.